User Archive Write Manager; Function Block "Fb_Ua_Wm - Siemens SIMATIC PCS 7 System Manual

3.3

User Archive Write Manager

The User Archive Write Manager consists of the "FB_UA_WM" function block and executes
the following functions:
● Writing one or more data records from an AS data block to an OS user archive on request.
● Monitoring communication (generation of alarms)
No picture objects are required for the User Archive Write Manager. Execution of the User
Archive Write Manager is triggered via the interconnected APF modules.
Note
An RM/WM module should run in a OB faster than the requesting blocks.
3.3.1

Function block "FB_UA_WM"

Upon request, the "FB_UA_WM" function block writes data to an OS user archive via the
"BSEND" communication block (SFB12).
The data to be written are copied from a requesting block. Communication between the
requesting block and the "FB_UA_WM" function block occurs at the AS level using the
"UDT_UA_W_REQ_ST" (request) and "UDT_UA_W_ST" (feedback) structures.
The "FB_UA_WM" function block can manage a maximum of 128 requests. Each request
occupies a separate structure input (UDT_UA_W_REQ_ST) in the block. The requesting block
transfers its uniquely identifying ID (REQ_ID) to the structure.
The feedback in response to a write request is stored in a structure output (UDT_UA_W_ST)
and identified with the REQ_ID associated with the job. As a result, the requesting block is
able to detect that the feedback data belong to its write request.
OS tags are used to coordinate the data communication between the AS and OS. Appropriate
scripts associated with the "FB_UA_WM" function block and its functionalities are triggered for
operator control at the OS level.
Advanced Process Functions Engineering Manual
System Manual, 07/2016, A5E38719921-AA
Configuring AS-OS communication
3.3 User Archive Write Manager
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